- ID:
- ivo://CDS.VizieR/J/ApJ/706/1277
- Title:
- Stromgren photometry in {omega} Cen
- Short Name:
- J/ApJ/706/1277
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new intermediate-band Stromgren photometry based on more than 300 u, v, b, y images of the Galactic globular cluster {omega} Cen. Optical data were supplemented with new multiband near-infrared (NIR) photometry (350 J, H, Ks images). The final optical-NIR catalog covers a region of more than 20x20arcmin squared across the cluster center. We use different optical-NIR color-color planes together with proper-motion data available in the literature to identify candidate cluster red-giant (RG) stars. By adopting different Stromgren metallicity indices, we estimate the photometric metallicity for ~4000 RGs, the largest sample ever collected. We identify four distinct subpopulations, namely, MP ([Fe/H]<=-1.49), metal-intermediate (MI; -1.49<[Fe/H]<=-0.93), metal-rich (MR; -0.95<[Fe/H]<=-0.15), and solar metallicity ([Fe/H]~0). The last group includes only a small fraction of stars (~8%+/-5%) and should be confirmed spectroscopically. Moreover, using the difference in metallicity based on different photometric indices, we find that the 19%+/-1% of RGs are candidate CN-strong stars.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/458/4162
- Title:
- Stromgren photometry of M3 (NGC5272)
- Short Name:
- J/MNRAS/458/4162
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Stroemgren photometry of the Galactic Globular Cluster M3 to study its multiple generations phenomenon. The use of different colour-magnitude diagrams (CMDs) and especially of the notoriously efficient c_y_ index allowed us to detect a double red giant branch in the cluster CMD. After decontamination from fore- and background sources, the two sequences turned out to be equally populated. The two components also show a bimodal radial distribution well corresponding to that predicted by numerical simulations for clusters living in an intermediate dynamical evolutive state and with a population with modified chemical composition that was born more centrally concentrated than the primordial. The analysis of high-resolution spectra quantitatively demonstrates that the two detected sequences correspond to the first (Na-poor) generation and the second (Na-rich) generation, thus confirming the importance of synergy between photometry and spectroscopy.
- ID:
- ivo://CDS.VizieR/J/AJ/129/872
- Title:
- Stromgren photometry of NGC 2243
- Short Name:
- J/AJ/129/872
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD photometry on the intermediate-band uvbyCaH{beta} system is presented for the metal-deficient open cluster NGC 2243.
- ID:
- ivo://CDS.VizieR/J/AJ/120/3111
- Title:
- Stromgren photometry of NGC 6397
- Short Name:
- J/AJ/120/3111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD photometry extending below the turnoff of the globular cluster NGC 6397 on the uvbyH{beta} system is presented and analyzed. Restricting the sample to stars with small photometric errors and highly probable cluster membership, the reddening from approximately 1500 stars at the turnoff is E(b-y)=0.127+/-0.002 (standard error of the mean), equivalent to E(B-V)=0.179+/-0.003. The photometric abundance for the same sample, on the revised spectroscopic scale for globular clusters, is [Fe/H]=-1.82+/-0.04 (standard error of the mean). From 220 cluster red giants, well-defined relations are established for m_1_ and c_1_ as a function of b-y.
- ID:
- ivo://CDS.VizieR/J/AJ/125/1383
- Title:
- Stromgren photometry of NGC 6253
- Short Name:
- J/AJ/125/1383
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD photometry on the intermediate-band uvbyCaH system is presented for the old open cluster NGC 6253. Despite a high level of field star contamination because of its location toward the Galactic center, combination of the data from the multiple color indices with the core cluster sample derived from radial star counts leads to the identification of a set of highly probable, single cluster members.
- ID:
- ivo://CDS.VizieR/J/AJ/131/461
- Title:
- Stromgren photometry of NGC 2420
- Short Name:
- J/AJ/131/461
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD photometry on the intermediate-band vbyCaH{beta} system is presented for the metal-deficient open cluster NGC 2420. Restricting the data to probable single members of the cluster using the CMD and the photometric indices alone generates a sample of 106 stars at the cluster turnoff.
- ID:
- ivo://CDS.VizieR/J/AJ/127/1227
- Title:
- Synthetic Stroemgren photometry
- Short Name:
- J/AJ/127/1227
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A new grid of theoretical color indices for the Stroemgren uvby photometric system has been derived from MARCS model atmospheres and SSG synthetic spectra for cool dwarf and giant stars having -3.0<=[Fe/H]<=+0.5 and 3000<=T_eff_<=8000K. In the present investigation, we have also analyzed the observed Stroemgren photometry for the classic Population II subdwarfs, compared our "final" (b-y)-Teff relationship with those derived empirically in a number of recent studies and examined in some detail the dependence of the m1 index on [Fe/H].
- ID:
- ivo://CDS.VizieR/J/ApJ/690/163
- Title:
- The first Swift UV-Opt GRB afterglow catalog
- Short Name:
- J/ApJ/690/163
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first Swift Ultraviolet/Optical Telescope (UVOT) gamma-ray burst (GRB) afterglow catalog. The catalog contains data from over 64000 independent UVOT image observations of 229 GRBs first detected by Swift, the High Energy Transient Explorer 2 (HETE2), the International Gamma-Ray Astrophysics Laboratory (INTEGRAL), and the Interplanetary Network (IPN). The catalog covers GRBs occurring during the period from 2005 January 17 to 2007 June 16 and includes ~86% of the bursts detected by the Swift Burst Alert Telescope (BAT). The catalog provides detailed burst positional, temporal, and photometric information extracted from each of the UVOT images. Positions for bursts detected at the 3{sigma} level are provided with a nominal accuracy, relative to the USNO-B1 catalog, of ~0.25". Photometry for each burst is given in three UV bands, three optical bands, and a "white" or open filter. Upper limits for magnitudes are reported for sources detected below 3{sigma}. General properties of the burst sample and light curves, including the filter-dependent temporal slopes, are also provided.
- ID:
- ivo://CDS.VizieR/J/MNRAS/466/3636
- Title:
- The young open cluster NGC 7067
- Short Name:
- J/MNRAS/466/3636
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- NGC 7067 is a young open cluster located in the direction between the first and the second Galactic quadrants and close to the Perseus spiral arm. This makes it useful for studies of the nature of the Milky Way spiral arms. Stromgren photometry taken with the Wide Field Camera at the Isaac Newton Telescope allowed us to compute individual physical parameters for the observed stars and hence to derive the cluster's physical parameters. Spectra from the 1.93-m telescope at the Observatoire de Haute-Provence helped to check and improve the results. We obtained photometry for 1233 stars, individual physical parameters for 515 and spectra for 9 of them. The 139 selected cluster members lead to a cluster distance of 4.4+/-0.4kpc, with an age below log10(t(yr))=7.3 and a present mass of 1260+/-160M_{sun}_. The morphology of the data reveals that the centre of the cluster is at (RA, DE) = (21:24:13.69, +48:00:39.2) J2000, with a radius of 6.1-arcmin. Stromgren and spectroscopic data allowed us to improve the previous parameters available for the cluster in the literature.
- ID:
- ivo://CDS.VizieR/II/36
- Title:
- UBV and uvby-beta observations of Orion OB1 Association
- Short Name:
- II/36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Catalogue of Individual UBV and uvby-beta Observations of Stars in the Region of the Orion OB 1 Association presents individual UBV observations of 106 stars in the vicinity of the Orion Nebula (the Sword region) and individual uvby-beta observations of 508 stars in all regions of the Orion OB 1 association. For the UBV data the stars are identified by their Brun (1935) numbers, with cross identifications to the chart numbers used in Warren and Hesser (1977); the uvby-beta stars are identified by the aforementioned chart numbers and HD, BD or P (Parenago 1954) numbers in that order of preference. The catalogue contains the data of all observations and is intended to provide data for investigations of variability in the Orion region. See <http://obswww.unige.ch/gcpd/ph01.html> for a full description of the UBV system, and <http://obswww.unige.ch/gcpd/ph04.html> for a description of uvby-beta system.
